Rotary kiln



Feb 1941- B. H. PUERNER ET AL 2,230,601

ROTARY K I LN Filed March 14, 1940 5 i 5 F i i Patented Feb. 4, 1941ROTARY KILN Bertram H. Puerner and Elijah C. Greisen, Wauwatosa, Wis.,assignors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., acorporation of Delaware Application March 14, 1940, Serial No. 323,853

6 Claims.

This invention relates to rotary kilns of the type utilized for burningcement clinker. The raw material is usually in the form of a slurrywhich is passed through a rotary kiln slightly inclined with thehorizontal from the feed end to .the discharge end thereof. In order todry this slurry, a portion of the kiln near the feed end thereof isusually provided with heat transmitting elements such as chains which,during the rotation of the kiln, dip into the slurry, transmitting heatthereto, and are then drawn out of the slurry to expose the slurryadhering to the chain to the hot gases passing through the kiln.

It has been found that these chains interfere with the flow of materialthrough the kiln, greatly limiting the capacity of the kiln, resultingin lowered efficiency. This invention overcomes this disadvantage byproviding material feeding means Within the kiln at the chain zone,thereby expediting the passage of material therethrough.

It is an object of this invention to provide a rotary kiln provided withmaterial feeding means within the chain zone thereof to expedite theprogress of material therethrough.

It is an object of this invention to provide a kiln having, adjacent thefeed end thereof, a material feeding zone, a combined chain and materialfeeding zone, and a chain zone, in sequence.

It is another object of this invention to provide a kiln havingconnecting means carried by the shell of the kiln and extending inwardlythrough the refractory lining of the kiln, conveying means supported bysaid connecting means adjacent the kiln lining, and chains carried bythe conveying means.

Other objects of this invention will become apparent from the followingdetailed description, taken in connection with the drawing, wherein:

Fig. 1 is a vertical elevation sectional view of a kiln constructed inaccordance with this invention;

Fig. 2 is a vertical section taken at right angles to the view of Fig.l, on the line IIII thereof;

Fig. 3 is an enlarged detail view of a kiln section showing the meansfor attaching feeding means and chains to the kiln;

Fig. 4 is a view similar to Fig. 3 but taken at right angles thereto;and

Fig. 5 is a plan view of the detail shown in Figs. 3 and 4.

Referring to the drawing in detail, Fig. 1 shows a section of the kilnadjacent to the feed end thereof which is assumed to be at the left ofFig. 1. Near the feed end of the kiln zone A is shown as being providedwith feeding means which may consist of helical ribs, zone B is shown asbeing provided with feeding means and chains, while zone C is providedwith chains only.

The kiln consists of a generally cylindrical shell ll provided withrefractory lining l2. Attached to the shell are connecting blocks 13,which may consist of U-shaped blocks l4 suitably supported by the shellII and being provided with extension plates l5 which may be welded toblocks M. The feeding means may consist of a plurality of helicalflights I! which may be bolted to plate [5 by means of bolts l8. Helicalflights l1 are provided with apertures [9 to facilitate connection ofchains 20, 2| thereto. These chains may consist of relatively shortlengths 20 and longer lengths 2|, and may be arranged in the mannerdisclosed in the patent to R. C. Newhouse, 2,059,- 1'76, October 27,1936.

It will be understood that as material is fed into the feed end of thekiln, progress of material through the kiln is expedited in zone A bymeans of feeding means IT. This greatly increases the capacity of thekiln. The material, usually in the condition of a wet slurry, thenpasses through the combined chain and feeding means zone B in which thechains assist in drying the wet material while the feeding means ll aidsin advancing the material axially of the kiln. By the time the materialhas passed through the zone designated by the letter B, it is relativelydry and auxiliary feeding means are no longer required. Thereforesection C consists of chains alone.

The helical ribs or flights I! serve not only to advance the materialwithin the kiln but also serve as heat transmitting media. In actualinstallations it has been estimated that as much as 20 per cent of theheat transmitting effect is due to the helical ribs ll.

While the chains may be connected in any desired manner, it has beenfound desirable to connect the chains so that they will be suspended inplanes at right angles to the axis of the kiln, as described in moredetail in said Newhouse Patent, 2,059,176. In order to avoid unnecessarywear between the chains and the refractory kiln lining, the length ofindividual chains is made substantially equal to the distance betweenthe points of attachment of the ends of the chains, as measured alongthe inner surface of the kiln. For example, a 90 chain-that is, a chain20 having its ends connected to points in the kiln spaced by 90has alength substantially equal to one-fourth of the circumference of theinterior of the kiln.

While the disclosure herein refers to a specific construction, it is tobe understood that numerous modifications which will occur to thoseskilled in the art are included within the spirit of this invention andin the scope of the claims appended hereto.

It is claimed and desired to secure by Letters Patent:

1. A rotary kiln comprising treating zones arranged in the followingsequence: feed end; a zone provided with helical ribs; a zone providedwith helical ribs and chain sections; and a zone provided with chainsonly.

2. In a rotary kiln, a kiln shell, a refractory lining within saidshell, a chain section comprising connecting means carried by the kilnshell and passing through said refractory lining,

helical ribs carried by said connecting means interiorly of said kilnlining, and a plurality of chains supported by means including saidnecting means.

3. In a rotary kiln, a kiln shell, a refractory lining within said kilnshell, connecting means carried interiorly of said kiln shell andpassing through said lining, helical material conveying ribs supportedon the inner surface of said lining by said connecting means, and aplurality of chains carried by said helical ribs.

4. A rotary kiln comprising a shell lined with refractory materialinteriorly thereof, individual connection blocks carried by said shelland extending inwardly beyond the surface of said refractory lining, aplurality of helical flights, and means for connecting said helicalflights in position adjacent to the inner surface of said lining on saidextending blocks, whereby said helical flights are attached to saidcasing independently of said refractory lining.

5. A rotary'kiln comprising a generally cylin- .drical shell, providedwith a refractory lining interiorly thereof, a plurality of connectingblocks located within said shell and extending inwardly beyond the innersurface of said lining, a plurality of helical flights adjacent theinner surface of said inner lining, each of said flights being attachedat its ends to at least two connecting blocks which are axially andcircumferentially spaced from each other, and a plurality of chainswithin said kiln, each of said chains being fastened at its end to twoflights at points circumferentially spaced from each other.

6. A rotary kiln as defined in claim 5 wherein said chains are mountedin planes normal to the axis of rotation of said kiln.

BERTRAM H. PUERNER. ELIJAH C. GREISEN.

